In a low-voltage and high-current condition, a synchronous rectifier instead of an ordinary diode may be employed to reduce the power loss of a circuit. However, a synchronous rectifier may often be disturbed by parasitic parameters or noises during an operation resulting in undesirable repeated conduction and blocking switching in one operating cycle. For example, in an LLC resonant converter with a transformer having a dual-channel secondary side, wherein each channel includes a synchronous rectifier, the LLC resonant converter may generate ringing once one of the two synchronous rectifiers is disturbed by parasitic parameters or noises. In this circumstance, a normal on and off switching of the synchronous rectifiers in the dual-channel of the secondary side will be interrupted. Furthermore, the two synchronous rectifiers may have undesirable repeated conduction and blocking switching in one operating cycle, even causing the two synchronous rectifiers both turned on.
Accordingly, a control circuit for a synchronous rectification circuit and associated control method are desired.